base64.js

base64.js

let characters = "0123456789abcdefghijklmopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ+/"

function encode64(num)
{
    let BASE = 64; //Define the base to convert num to

    let string = "";

    let i = 0;
    let cont = true;

    while (cont)
    {
        //If num is smaller than base ** (iteration + 1), we can continue
        if (num < Math.pow(BASE, i + 1))
        {
            let sum = 0;

            let floor = Math.floor(num / Math.pow(BASE, i)); // Drop the decimal part from num / base ** iteration
            let sum = Math.pow(64, i) * floor; // Multiply result by base ** iteration

            let a = i;

            while (i >= 0)
            {
                floor = Math.floor(num / Math.pow(BASE, i));
                floor2 = Math.floor((num - sum)) / Math.pow(BASE, i);
                sum = Math.pow(BASE, i) * floor;

                // If a == i, append characters[floor], otherwise characters[floor2], to string
                (a == i) ? string += characters[floor] : string += characters[floor2];

                i--;
            }

            cont = false; // If i < 0 we want don't continue
        }

        i++;
    }

    return string;
}